The United States of America is a federal democratic republic situated primarily in North America. It is comprised of 50 states and one federal district, and has several territories. It is also referred to, with varying formality, as the United States, the U.S., the U.S.A., the States, or simply and most commonly, America.

Since the mid-20th century, following World War II, the United States has emerged as a dominant global influence in economic, political, military, scientific, technological, and cultural affairs. Because of its influence, the U.S. is considered a superpower and, particularly after the Cold War, a hyperpower by some.

Economy

The United States has the largest single-country economy in the world. [1] In this market-oriented economy, private individuals and business firms make most of the decisions, and the federal and state governments buy needed goods and services predominantly in the private marketplace. This is financed via taxes and borrowings in the money market. Federal borrowings are subject to borrowing caps to theoretically prevent fiscal irresponsibilty.

The largest industry in the U.S. is now service, which employs roughly three quarters of the work force. The United States has many natural resources, including oil and gas, metals, and such minerals as gold, soda ash, and zinc. In agriculture, it is is a top producer of, among other crops, corn, soy beans, and wheat; the United States is a net exporter of food. The manufacturing sector produces goods such as, cars, airplanes, steel, and electronics, among many others.

Economic activity varies greatly from one part of the country to another, with many industries being concentrated in certain cities or regions. For example, New York City is the center of the American financial, publishing, broadcasting, and advertising industries. Silicon Valley is the country's largest high technology hub, while Los Angeles is the most important center for film production. The Midwest is known for its reliance on manufacturing and heavy industry, with Detroit, Michigan, serving as the center of the American automotive industry. The Great Plains are known as the "breadbasket" of America for their tremendous agricultural output; the intermountain region serves as a mining hub and natural gas resource; the Pacific Northwest for fish and timber, while Texas is largely associated with the oil industry; and the Southeast is a major hub for both medical research and the textiles industry.

Several countries continue to link their currency to the dollar or even use it as a currency (such as Ecuador), although this practice has subsided since the collapse of the Bretton Woods system. Many markets are also quoted in dollars, such as those of oil and gold. The dollar is also the predominant reserve currency in the world, and more than half of global reserves are in dollars.

The largest trading partner of the United States is Canada (19%), followed by China (12%), Mexico (11%), and Japan (8%). More than 50% of total trade is with these four countries.

Labor unions have existed since the 19th century, and grew large and powerful from the 1930s to the 1950s. Since 1970 they have shrunk in the private sector and now cover fewer than 8% of the workers. However union membership has grown rapidly in the public sector, especially among teachers, nurses, police, postal workers, and municipal clerks. There have been few strikes in recent years. The most recent was an illegal one that occured in New York City in December of 2005 by transit workers.

Since the 1980s, the U.S. has increased the use of neoliberal economic policies that reduce government intervention and reduce the size of the welfare state, backing away from the more interventionist Keynsian economic policies that had been in favor since the Great Depression. As a result, the United States provides fewer government-delivered social welfare services than most industrialized nations, choosing instead to keep its tax burden lower and relying more heavily on the free market and private charities.

Education

In the United States, education is a state, not federal, responsibility, and the laws and standards vary considerably. However, the federal government, through the Department of Education, is involved with funding of some programs and exerts some influence through its ability to control funding. In most states, all students must attend mandatory schooling starting with kindergarten, which children normally enter at age 5, and following through 12th grade, which is normally completed at age 18 (although in some states, students are permitted to drop out upon the age of 16 with the permission of their parents/guardians). Parents may educate their own children at home (with varying degrees of state oversight), send their children to a public school, which is funded with tax money, or to a private school, where parents must pay tuition. Public schools are highly decentralized with funding and curriculum decisions taking place mostly at the local level through school boards.

After high school, students may choose to continue their schooling at a public/state university or a private university. Public universities receive funding from the federal and state government but students still pay tuition, which can vary depending on the university, state, and whether the student is a resident of the state or not. Tuition at private universities tends to be much higher than at public universities. It is not uncommon for students to join the workforce or the military before attending college; both the military and many private employers may subsidize post-secondary education.

American colleges and universities range from highly competitive schools, both private (such as Harvard University and Princeton University) and public (such as the University of California, Berkeley and the University of Virginia), to hundreds of high-quality local community colleges with open admission policies. There is also a subgroup of sociology/anthropology popular in American colleges and universities today called American studies.

Culture

U.S. popular culture has a significant influence on the rest of the world, especially the Western world. U.S. music is heard all over the world, and it is the sire of such forms as blues and jazz and had a primary hand in the shaping of modern rock and roll and popular music culture. Many great Western classical musicians and ensembles find their home in the U.S. New York City is a hub for international operatic and instrumental music as well as the world-famed Broadway plays and musicals. Nashville is the center of the country music industry. Another export of the last 20 years is hip hop music, which is growing in influence and branching into the fashion, food and drink and movie industries. New York, Seattle, and San Francisco are worldwide leaders in graphic design and New York and Los Angeles compete with major European cities in the fashion industry.

U.S. movies (primarily embodied in Hollywood) and television shows can be seen almost anywhere except the most totalitarian places.

Nearing the mid-point of its third century of nationhood, the U.S. plays host to the gamut of human intellectual and artistic endeavor in nearly every major city, offering classical and popular music; historical, scientific and art research centers and museums; dance performances, musicals and plays; outdoor art projects and internationally significant architecture. This development is a result of both contributions by private philanthropists and government funding.

American holidays are variously national and local. Many holidays recognize events or people of importance to the nation's history; as such, they represent significant cultural observance.

Sports

The major team sports in America are home-grown. American football, baseball (often called "The National Pastime"), auto racing (especially NASCAR), and basketball, are the top four main sports in America. Ice hockey is also popular in the U.S., especially in Minnesota and the Northeast. Soccer does not have a particularly large following in the U.S. (in contrast to its extreme popularity in most other countries), but nevertheless, the U.S. did host the World Cup in 1994. Soccer continues to grow in the U.S., and is currently one of the most played sports amongst youth. The majority of the world's highest paid athletes play team sports in America [2].

The United States also hosts large followings of traditional European sporting events. Horse racing is popular in the United States as a gambling event, and the United States hosts several world renowned horse racing events, including the Kentucky Derby. Other European sports such as polo have minor leagues.

The United States hosts some of the premier events in other sports such as golf (including three of the four majors), and tennis (the U.S. Open). The most popular form of auto racing is NASCAR. Formula One, while dominant in the rest of the world, has only made limited inroads into the U.S. market. The only Formula One event currently in the U.S. is the United States Grand Prix. However, the visually similar Indy 500 is the nation's most famous racing event, and both the U.S. Grand Prix and the Indy 500 currently take place at the Indianapolis Motor Speedway.

In the 20th century, the United States became the center of the two most popular Western combat sports - boxing and wrestling. Boxing is popular as both a spectator sport and a gambling event. The United States has produced many famous boxers who have become public figures in their own right, such as Muhammad Ali and Mike Tyson. The United States has also contributed immensely to the popularity of the mostly theatrical professional wrestling. Professional wrestling is widely popular in America, but is considered mainly a form of scripted entertainment rather than a true sport. Other combat sports based on Asian martial arts, such as karate competitions, maintain large national leagues and hold frequent competitions.

The United States is also credited in creating the three popular board-based recreational sports - surfboarding, skateboarding and snowboarding. While first practiced by native Hawaiians, Americans were almost solely responsible for creating surfboarding's worldwide popularity. Skateboarding and snowboarding are completely modern American inventions, and all three have given rise to national competitions and a large dedicated subculture. Snowboarding is the only one of the three to become Olympic event, beginning with the Winter Olympics in 1998.

Eight Olympic Games have been hosted in the U.S., more than in any other nation. The United States generally fares very well in the Olympics, especially the Summer Olympics: in 2004, the U.S. topped the medals table with a record 103 medals (35 gold, 39 silver and 29 bronze). This is especially astonishing when taken in comparison with countries that usually perform very poorly at the Olympics, such as Canada, which only collected 12 medals (3 gold, 6 silver and 3 bronze) in 2004.

During times of extreme popularity certain teams have been (unofficially) crowned "America's team." The New York Yankees, the Chicago Bulls, and the Dallas Cowboys are examples of teams that have reached this status.

American college sports are nearly as popular as professional sports, particularly college football and college basketball. American colleges often support wide-ranging sports programs, including track and field and more eclectic sports such as water polo, as well as the more popular sports such as football and baseball.